Hi people,
Need some help with the following sums i found on Kaplan mock papers. I'v given the answers along with the sums... I cant arrive at the answers
Data Sufficiency:
1) If k not equal to 0, 1 and -1, then is 1/k > 0 ?
i) 1/ (k-1) > 0
ii) 1/ (k+1) > 0
Ans: Only statement (i) is sufficient.
2) Martha bought pencils, some worth 23 cents and some worth 21 cents. How many pencils of price 23 cents did she buy?
i) Martha bought a total of 6 pencils
ii) The total value of pencils is 130cents
Ans: Only statement (ii) is sufficient. ( i thought both statements were needed)
3) Is l x-y l > lxl - lyl ?
i) y < x
ii) xy < 0
Ans: Only statement (ii) is sufficient.
4) Is m + z > 0 ?
i) m-3z > 0
ii) 4z-m > 0
Ans: Both statements are needed to arrive at answer.
5) If n and m are positive integers, what is the remainder when [3 (raised to) 4n+2] + m is divided by 10?
i) n = 2
ii) m = 1
Ans: Statement (ii) alone is sufficient.
Problem Solving:
1) If d is the standard deviation of x, y and z, what is the standard deviation of x+5, y+5 and z+5 ?
Options: d, 3d, 15d, d+5, d+15 ?
Ans: d
2) A certain city with a population of 132,000 is to be divided into voting districts, and no district is to have a population that is more than 10% greater than the population of any other district. What is the minimum possible population that the least populated district could have?
Options: 10700, 10800, 10900, 11000, 11100
Ans: 11000
3) The rate of a certain chemical reaction is directly proportional to the square of the concentration of Chemical A present, and inversely proportional to the concentration of Chemical B. If the concentration of Chemical B is increased be 100% what should be the increase/decrease in the concentration of Chemical A to keep the reaction unchanged?
Ans: 40% increase.
4) Score Intervals:50 - 59 : 2
60 - 69 : 10
70 - 79 : 16
80 - 89 : 27
90 - 99 : 18
Which score interval contains the median of the 73 scores?
Ans: 80-89
Would appreciate the help... Thanks.
